Process of making lath board



G. H. ELLIS.

PROCESS 0F MAKING LATH BOARD.

APPLlcAloN FILED Nov.22, 1920.

LASU l Patented Dec. 5, 1922.

I/v VEN rolf.

G50/fes H. 2L/5.

Patented Dec. 5, i922.

TENT

GEORGE H. ELLIS, OF ST. PAUL, MINNESOTA.

vPROCESS OF MAKING LATH BOARD. I

Application iled November 22, 1920. Serial No. 425,894.

To aZZ whom t may concern.' y

Be it known that I, GEORGE H. ELLIS, a citizen of the United States, residing at St. Paul, in the county of Ramsey and State of Minnesota, have invented certain new and useful Improvements in Processes of Making Lath Board; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to a method of makingan insulating plaster board. Such boards are now commonly commercially used for holding plaster or stucco, both in interior and exterior building construction.

It is an object of this invention to provide a board with which the plaster will be positively interlocked and one constructed of such material that the laster will not be cracked thereon during t e setting and drying stage.

is a further object of this invention to provide a board which will be of suiicient rigidity to form an efficient lath board and which can be made in sections of considerable area. V

These andI other objects of the invention will become apparent from the following description made in connection with the accompanyi'ng drawings, in which Fig. 1 is a plan view of the apparatus shown in Fig. 2, certain parts being omitted.

Fig. 2 is a sectional View of one form of apparatus used for carrying out the method, said section being taken in a point of the apparatus indicated by the llne 2--2` of Fig. 1

ig. 3 is a sectional view of a portion of the completed board4 showing` plaster attached thereto.

The improved insulated lath board may pulped waste paper, which paper may bev easily obtained in large quantlties lat low cost inpractically all countries and especially in the United States.

In using the waste paper, the sulphite and better grades of paper can be sortedand reused to make a high grade paper, while the colored paper may be sorted out and the d1e stock reclaimed therefrom. By this practice, the salvage obtained in handling the paper will pay for the cost of the same, so-that the portion of paper used in making the lathboard' costs practically nothing. l/Vaste paper also contains sizing which, to a considerable degree, renders the board made therefrom waterproof. The waste paper is pulped, but need not be, and preferably is not entirely disintegrated. It is, however,- reduced to a pulp of such character that it may be molded or pressed to the desired form. y

In constructing the board by the vpresent method, the same is formed with interlocklng depressions with which the plaster is designed to engage. These interlocking depressions are preferablyinade in the form of parallel dove-tailed grooves. The structure and material of the board must be such that, in addition to having the plaster interlocked therewith, the same must be capable of expansion and compression under a force less t-han that which will crack the plaster. If this is not the case, the plaster will crack when it is setting or hardening on the board. The board produced by the present method possesses the desired qualities in a high degree, and furthermore, the parallel dovetailed grooves therein, as will be hereinafter set forth, renders the board coherent, rigid and of suicient strength.

One form of apparatus is capable of use fon carrying out the method as shown in Figs. 1 and 2, but it is obvious that other' forms of apparatus may he used.

box-like mold having the walls 1 is provided and this box is provided at the corners thereof with depending lugs and a air of bars 2 are pivoted at one end to the ugs in one side of the box. The bars 2 carry blocks 3 having T-shaped openings extending therethrough, and in wiich o enings are disposed a series of spaced core ars 4. rlhe blocks 3 are connected by transverse rib members 5, the top surface of which supports a screen 9 which extends between the core bars 4 and forms the bottoni of the mold. As clearly shown in Fig. :2. the core tailed grooves. The bars extend to one side of the wall and are firmly connected together by the member 7 to which they are firmly secured. The bars 2 which carry the blocks 3 and core barsfi can be swung on the pivot at one side of the walls and at the other side thereof, are adapted to be disposed between the lugs on the mold and to receive a pin 8 which extends through aligned openings formed in the bars and the lugs in themold to hold the same in proper position. It will be noted also from the described construction, that the core bars 10 can be withdrawn endwise from the mold by means of member 7. Vith the mold arranged, as shown in Fig. 2, the soft mold able material formed from the Waste paper pulp is placed on the screen 9 to a sufficient depth to provide the desired thickness of board and another screen member 6 carried in a suitable frame l0 and which closely fits the inside of the walls l, is placed on the.

material and pressed down by hand, or any other suitable means. The moisture is thus expressed from the material and the same is compressed and compacted to a desired degree. Vifhen the material is suitably pressed, the core bars 10 will be withdrawn lengthwise, the mold ma then be inverted, the bars 2 lifted, carrying therewith the blocks 3, rib members 5 and screen 9. The board can then be left in position on the screen 6 until it is suitably dried.

In forming the board, as described, it will be noted that the top of the bar's 10 are comparatively close to the top pressing screen 6. Since the material being compressed is not a fluid, this results in the portion of the board lying between the top of the bars 4 and the screen 6 being compressed to a greater degree than the remaining portions which are of greater thickness. Owing to the fibrous nature of the material and the interlocking of the fibers therein, the fibers in said portion between the top of bars 4 and screen 6 will not be displaced but will be more closely compacted and whenthe board is dry will form zones of greater strength and rigidity. The board is thus provided with a series of spaced longitudinal sections extending thereacross, of greater hardness and strength than the remaining portions which form, in reality. strengthening ribs. These strengthening ribs extending across the board add very materially to its rigidity, strength and resistance to breakage in the necessary handling thereof.

After the board has been properly dried, the grooved surface may be coated or impregnated with any desired water-proofing material, such as a coal tar, varnish, or any of the well known water proofing substances.

It is thus seen that applicant has produced a lath board of great efficiency and one which will expand and contract under various degrees of moisture and temperature and which is also of such texture and consistency that it will be compressed by the plaster when the same shrinks and dries so that the plaster will not be cracked. Such a board has been found greatly superior to either the wooden or metal structures which have been used as lath boards. Y

The lath board made by the method disclosed herein not only has the capacity for positively holding the plaster without cracking, but also has great insulating capacity. Such a board, therefore, performs both the function of sheathing and of lath and may be used either inside or outside of a building without the use of wooden sheathing or sheathing of any other kind. It is, of course, of great value when used with sheathing, and where eXtra strength and insulation are desired, it will be thus used. It will be understood that various changes may be made in the steps of the process and in the order thereof without departing from the scope of applicants invention which, generally stated, consists in the matter shown and described and set forth in the appended claims.

What is claimed is:

l. The process of making insulating lath board which consists in providing core bars of dove-tailed section, placing the same in spaced relation transversely on the screen bottom of a mold, placing on said screen and bars a soft moist fibrous material and pressing said material with a flat pressing member, the material being such that the fibers thereof are not displaced over said bars but are more closely compacted, withdrawing the core bars lengthwise from the material, and"removing the material from themold by inverting the same, and drying said molded material.

2. The process of forming an insulating lathboard 'having locking grooves therein which consists in pressing the soft, moist and moldable fibrous material between the top and bottom of a perforate mold in which are placed spaced upstanding bars of the shape of the interlocking groove, whereby the material above the core bars owing to its fibrous nature is not displaced but is pressed to greater compactness than the remaining material, removing the material from the mold and drying the same so that a board is formed having spaced narrow zones in which the material is harder and stiffer than the remaining portions of the board.

3. The method of making grooved insulating lath" board which consists in pressing the soft moist and moldable fibrous material between the top and bottom perforated pressing members of a mold, on the bottom of' which are inserted upstanding core bars that are of greater width in cross section at their tops than adjacent the bottom of the mold, the fibers of said material notbeng dis placed over said bars but becoming more compacted, removing said material from the mold and drying the same whereby is formed a board having spaced transverse narrow zones of great hardness, and the edges of the slots of which are quite porous, compressible and expansible.

4. The process of forminglathboard from disintegrated fibrous material consisting- Vin pressing the soft wet fibrous material in a sheet to express the liquid therefrom., forming transverse grooves in said sheet and compressing the bers of the material at the top of said grooves to a greater extent than the remainder of the sheet whereby the material owing to its fibrous nature is not displaced but forms narrow spaced strengthelr ing zones in said sheet.

5. The process of making' lath oi disintegrated ibrouslmaterial which consists in pressing a layer'of soft moist material in a mold between perforated plate members. one of which is provided with spaced upstand- .ing transversely extending means to form grooves in the material of substantial dovetailed shape in cross section whereh \Y thc material on top of said means owing to iis fibrous nature is not displaced but is compressed more than the remaining; material to form strengthening strips of a greater degree `of hardness than the remainingv portions of the board. l

In testimony whereof I afl-ix mv signature.

GEORGE Hf ELLIS. 

